Method of forming needle-penetrable stoppers for containers



Dec. 28, 1954 H. H. CLAPP EI'AL METHOD OF FORMING NEEDLE-PENETRABLESTOPPERS FOR CONTAINERS 8 Sheets-Sheet 1 Filed Sept. 29, 1950 Fmz;

INVENTORS RiCHARD J DENNEY HENRY H. CLAPP ATTORN Dec. 28, 1954 H. H.CLAPP EIAL 2,698,272

METHOD OF FORMING NEEDLE-PENETRABLE STOPPERS FOR CONTAINERS Filed Sept.29. 1950 Sheets-Sheet 2 INVENTORS Dec. 28, 1954 H. H. CLAPP EIAL 2,698,7

METHOD OF FORMING NEEDLE-PENETRABLE STOPPERS FOR CONTAINERS Filed Sept.29, 1950 8 Sheets-Sheet 3 FIC.6.

INVENTORS RICHARD J. DENNEY HENRY H. GLAPP 1954 H. H. CLAPP ETAL2,698,272

METHOD OF FORMING NEEDLE-PENETRABLE STOPPERS FOR CONTAINERS Filed Sept.29, 1950 v 8 Sheets-Sheet 4 INVENTORS "I RICHARD \J.DENNEY HENRY H. am

ATTORN EY 1954 H. H. CLAPP ETAL 2,698,272

umuon 0F FORMING NEEDLE-PENETRABLE STOPPERS FOR CONTAINERS Filed Sept.29. 1950 8 Sheets-Sheet 5 INVENTOR$ R 'HRD J. DENNEY NgY H.CLAPP ATTOR YDec. 28, 1954 H. HJCLAPP ETAL 2,698,272

METHOD OF FORMING NEEDLE-PENETRABLE STOPPERS FOR CONTAINERS Filed Sept.29, 1950 8 Sheets-Sheet 6 Dec. 28, 1954 H. H. CLAPP mm.

METHOD OF FORMING NEEDLE-PENETRABLE STQPPERS FOR CONTAINERS Filed Sept.29, 1950 8 Sheets-Sheet 7 INVENTORS PICHHRD J. DENNEY HENRY H- CLAPPDec. 28, 1954 H. CLAPP ETAL zfi fi METHOD OF FORMING NEEDLE-PENETRABLESTOPPERS FOR CONTAINERS Filed Sept. 29. 1950 8 Sheets-Sheet 8 r I q 107INVENTORS RICHHRD J. DENNEY HENRY H. CLAPP ATTORNE United States PatentMETHOD OF FORMING NEEDLE-PENETRABLE STOPPERS F'OR CONTAINERS Henry H.Clapp, Philadelphia, and Richard J. Denney, 'Dreirel Hill, Pa.,.assignorsto The 'Gillon. Company, Inc., Philadelphia, 'Pa.,. a:corporation of Pennsylvania Appiicationseptember 29, 1950, Serial No.187,446 6Claims. (Cl. 15'4--1'10) The present invention relatesgenerally to needlepenetrable stoppers .for the aseptic sealing ofbottles, ainpoules or similar containers for biological andpharmaceutical liquids, powders and the. like and it relates moreparticularly to. a novel method of forming laminated needle-puncturableself-sealing stoppers, etc.

An object ofithe present invention .is to provide a novel methodofforming. a needle-penetrable sealing cap or stopper for a bottle.Another object of the present invention is to provide a new and improvedmethod for forming a laminated needle-penetrable sealing cap or stopperfor a bottle. 'Still another object of the present invention is toprovide a novel method forsecurely and effectively bonding a continuousand imperforate. film of chemically resistant and impervious syntheticresin to a soft-rubber sealing cap or stopper. A'further object of thepresent invention. isto provide a new and improved method for'forminglaminated needle-penetrable sealing caps or stoppers by eiiecting afirm, secure and continuous bond between a thermoplastic soft-rubbersurface and a thermoplastic synthetic resin surface, employing atherrnosetting adhesive composition. A still further object of thepresent invention is to provide a novel method for forming a laminatedneedle-penetrable sealing cap or stopper by moldingsoft-rubber into thedesired form, under the action of heat and pressure, and, simultaneouslytherewith, adhering tothe rubber a continuous and imperforate film ofthermoplastic resin, employing. an intervening thermo-setting adhesive.

Other. objects and advantages of the present invention are apparent inthe following detailed description, appended claims andaccompanyingdrawings.

It has been customary to package various biological and pharmaceuticalliquids in bottles or ampoules or like containers and .to provide suchbottles.-etc. with needlepierceable stoppers or caps of soft-rubberwhereby. the 11 contents can be withdrawn into a hypodermic syringe orlike instrument for administration to patients. However, theseconventional soft-rubber stoppers or. caps have not proven entirelysatisfactory because rubber-interacts (chemically or otherwise) with avconsiderable .number of pharmaceutical and biological liquids (such asare normally administered by a hypodermic syringe) with resultantcontamination of the liquid contents.

In our ctr-pending. application Serial No. 181,194, filed August24,1950, nowabandoned, I have disclosed a novel and unique construction forsuch a sealing cap or stopper, namely a laminated structure in whicha.relatively thin,flexiblegirnperforate, chemically-resistant andimpervious filmof nylon or other suitable thermoplastic synthetic resinis firmly and continuously adhered to at least'the underside and,optionally. also the uppers'ide) of a soft-rubber body; the syntheticresin-film and .the soft-rubberbody being effectively. bonded '(by. anintervening layer of adhesive material) into a moreortless unitarystructure having the desired resilience and tcompressibility of-therubber and'the chemical inertness and the smooth relativelynon-poroussurface of the synthetic resin.

The present application is directed to our novel method of forming thelaminated sealing cap or stopper of my aforesaid co-pending application.

"Generally speaking,.' the novel method of the present inventionincludes the. steps of placing a relatively thin film of nylon. or othersuitable thermoplastic synthetic resin next'to a body of soft rubber(natural or synthetic) (said body of r ubbereither beingini the form ofa con- 2,698,272 Patented Dec. 28, 1954 2 tinuous sheetorbeing in theform of pellets. or other discrete particles which will fuse togetherwhen heated) with a coating (either-continuous or dis continuous).-ofthermosetting adhesive on the juxtaposed face of the nylon film (or,optionally, on the juxtaposed face of the rubber sheet) .and, thensubjecting the juxtaposed. nylon and rubber to the action of heat andpressure so as to mold the soft rubber into the desired formwith,the.film forming a continuousandimperforate coveringor skin on oneside of the molded stoppenand. simultaneously to harden or set the.adhesive so as to create a firm and continuous bond. between; the. outerskin or film and. the molded soft rubber.

For the purpose of illustrating the invention, there are shown inthe;accompanying.drawingsforms thereof which are at presentpreferred,although it is to be understood that-the various instrurnentalities ofwhich the invention consists can. be variously arranged and organizedand that the-invention, is notlimited to the precise arrangements andorganizations of the instrumentalitiesas herein shown and described.

Referring tothe accompanying drawings in which like reference charactersindicate like partsv throughout:

Figure 1 represents a more-or less schematic fragmentary perspectiveview,showing aso ft-rubber sheetiand an adhesive-coated nylon filmas.they appear. prior to being brought together intermediate the sectionsof a heated pressure-mold; parts being broken away better toreveal theconstruction. thereof.

Figure 2 represents.- a vertical cross-sectional. view, on an enlargedscale, showing the appearance of the rubber sheet and nylon film whenthe heated mold-sections-have been brought together.

Figure 3 representsa fragmentary perspective view showing thefilm-covered side of the composite laminated structure after-it has beenremoved from the, mold.

Figure 4, represents a plan viewshowing the uncoated side of. the stripofFigure 3.

Figure 5 represents a perspective view of an individual stopper as itappearsafter it-.ha s, been; detached from the strip of Figures. 3..and-4.

Figure .6 represents a. cross-sectional view generally like that ofFigure 2, butshowing another embodiment.

Figure 7 represents; a,,per spective,view like that of Figure 3. butshowing the embodiment of Figure 6.

Figure 8 representsaperspective. view of an individual stopperas.;it..appears when idetachedfrom the strip of Figure 7.

Figure 9 represents a more or less schematic perspective' view generallylike. thatof Figure lsbut showing another embodimentof the present,invention wherein separate thin films of .nylonorthelike arepositionedon either side .ofthe rubber sheet.

Figure 10-represents-a cross-sectional view like that of Figure 2 butshowing the embodiment of Figure. 9.

Figure 11 represents aperspective. view of, an individualstopperasitappears when detached from the strip of Figure 10.

Figure l2- represents..across-sectional view generally like that ofFigure 2 but showin an intermediatestage in theprocess .for formingamodified'torm; of laminated stopper.

Figure 13 represents a perspective view of an individualSlZOD'OGl'zfOIII'lGdfIQIIl the strip of Figure 12.

Figure 14 .represents a cross-sectional view of a strip of stoppers ofanother embodiment of the invention.

Figure 15 represents a perspective view ofan'individual stop er ofFigure 14 Fi ure; 16 represents .a cross-sectional view generally likethat ofFigure 2, but showing anotherembodiment of the invention.

Figure 17 represents a perspective view of an individual stonoer ofFigure 16 Figure 18 represents a more or less schematic fragmentaryperspective view generally similar to Figure 1, but showing anotherembodiment of the invention.

Figure 19 represents a perspective view of an individual stonoer of theembodiment *shownin Figure 18.

FigureQZO represents a more or; less schematic-fragment ry pers ectiveview generally "like Figure l, but

.' showing another embodimentof the invention.

Figure 21 represents a cross-sectional view generally like Figure 2, butshowing the embodiment of the invention of Figure 20.

Figure 22 represents a perspective view of an individual stopper as itappears when detached from the strip of Figure 21.

Figure 23 represents a perspective view of the stopper of Figures 20, 21and 22, showing the use of a portion thereof.

Figure 24 represents a cross-sectional view generally like that ofFigure 2, but showing another embodiment of the invention.

Figure 25 represents a perspective view showing an individual stopper ofFigure 24.

Figure 26 represents a fragmentary perspective view, partly in section,showing an individual stopper of Figure 25 positioned in place upon abottle.

In Figure 1 there is shown, schematically, a heated pressure-mold madeup of a lower stationary section and an upper downwardly-movable section21; the sections 20 and 21 being provided with conventional concealedelectrical heating elements (not shown) whereby the sections can bemaintained at any desired elevated temperature.

The upper face of the lower mold-section 20 is recessed slightly as at22 in respect to a peripheral shoulder 23. The recessed portion 22 isprovided with a plurality of spaced generally cylindrical sockets orconcavities 24; the bottom generally fiat and circular wall of eachsocket 24 being grooved as at 26 to provide a marker on the finalstopper, as will be described hereinbelow.

The lower face 27 of the upper movable mold-section 21 is provided witha plurality of annular depressions 28 disposed in vertical alignmentwith the sockets 24 described above; a downwardly-extending convexsemispherical knob 29 being formed in the center of each annulardepression 28. An upwardly-tapered annular surface 30 is formed at theupper end of each annular depression 28.

A flat sheet 31 of heat-moldable relatively soft and resilientelastomer, i. e., rubber, is adapted to be positzigned above the upperface 22 of the lower mold-section A relatively thin flexible imperforatechemicallyresistant and non-porous film 32 of nylon or other suitablethermoplastic synthetic resin is adapted to be positioned above therubber sheet 31 with its lower face coated, as at 33, with a layer oftherrno-setting adhesive capable of bonding the nylon film to the rubbersheet under the action of heat and pressure.

A thermo-setting adhesive composition which can be employed for thispurpose may be formed as follows.

6.3 parts (by weight) of 28% ammonium hydroxide is added to 28 parts of62.5% crude latex, with stirring, after which the mixture is added (withstirring) to 46.4 parts of a resorcinol-formaldehyde reactioncomposition, which, for the purposes of nomenclature, may be designatedas the sub-batch. To the so resultant mixture is slowly added 2.9 partsof a 37% aqueous solution of additional formaldehyde, with continuedstirring. During addition of this formaldehyde, sufficient dilute (forexample 10% strength) sodium hydroxide solution is added from time totime to maintain the pH of the mixture at approximately 10.5.

One embodiment of the aforementioned sub-bate can be prepared asfollows:

1.6 parts (by weight) of resorcinol, 1.4 parts of a 37% solution offormaldehyde and 0.4 part of 10% sodium hydroxide solution are added to11 parts of hot water and the mixture is permitted to react, withstirring, for about 30 minutes at a temperature of approximately 130150F. At the end of this time, 8.8 parts of ice water (i. e. water at atemperature at or slightly above its freezing point) is added to themixture to reduce its temperature and to stop the reaction, after whichthe material is ready for use.

The adhesive-coated side 33 of the nylon (or other thermoplasticsynthetic-resin) film 32 is brought into contact with the upper surfaceof the rubber sheet 31, whereupon the upper movable mold-section 21 isbrought down under pressure (employing any conventional pressure-moldmechanism) until its lower face 27 makes surface contact with theshoulder 23 of the upper face of the lower mold-section 20.

The thickness of the sheet 31 is somewhat greater than 4 the depth ofthe recessed portion 22 so that when the mold-sections are closed, theheat-softened rubber is forced, by the pressure of the mold, into thesockets 24 and also into the annular depressions 28, so as completely tofill the sockets and depressions.

The nylon (or other thermoplastic synthetic resin) film 32 is alsosoftened by the heat of the mold and is forced into the annulardepressions 28 by the moldpressure to assume the configuration shown inFigure 2.

The nylon (or other thermoplastic synthetic resin) preferably has asomewhat higher softening point than the rubber so that, at thepredetermined mold temperature (approximately 385 to 320 F.) the nylondoes not become as fluid or plastic as the rubber. That is, the rubbershould become sufiiciently plastic to lose its form-retaining propertyand to permit it to be displaced into the sockets 24 and annulardepressions 28. The nylon film 32, on the other hand, should be softenedonly sufiiciently to permit it to be shaped to the configuration of theannular depressions 28 and knobs 29 while still retaining its cohesiveproperty as a continuous imperforate film of generally uniformthickness.

Under the action of the heat and pressure of the mold, the thermoplasticadhesive coating 33 hardens or sets so as to adhere to both the nylonand the rubber surfaces and thereby to create a continuous connectiontherebetween and thereby to give a securely bonded laminated structure.

In other words, the hardening or setting of the adhesive takes placegenerally simultaneously with the molding of the rubber and nylonsheets.

The mold is then opened and the composite two-ply laminated strip 34shown in Figures 3 and 4 is removed therefrom.

The strip 34 is made up of a plurality of stopper-portions 35 connectedby relatively thin webbing or flashing 36; one side of the strip 34being covered by the continuous nylon film 32 which has now been shapedinto the configuration of the lower face 27, annular depressions 28 andknobs 29 of the upper mold-section 21, as de scribed above.

The thickness of the nylon-coated webbing 36 corresponds generally tothe depth of the recess 22 and is appreciably less than the originalthickness of the rubber sheet 31. The other side of the strip 34, shownin Figure 4, is uncoated.

Each stopper-portion 35 includes an enlarged discshaped portion 37disposed on the uncoated side of the strip 34 and protruding downwardslightly therefrom; theportion 37 having been formed by the sockets 24.Each stopper-portion also includes a generally cylindncal portion 38, ofsmaller diameter than the portion 37 and extending upwardly on thecoated side of the strlp 34. An upwardly-tapered annular surface 39 isformed at the upper end of the portion 38 and a semi-spherical con cavesurface 40 extends downwardly from the top of the portion 38; an annularrim 41 separating the surfaces 39 and 40.

As can be seen particularly in Figure 2, the configuration of theportion 38 and the surfaces 39, 40 and 41 are formed by the annulardepression 28, the tapered surface 30 and the knob 29 of the uppermold-section 21.

As the final step in the forming process, each individualstopper-portion 35 is severed from the strip 34 by cuttlng the webbingalong the outer periphery of the disc-shaped portion 37. Anyconventional cutting or stamping mechanism (not shown) can be employedfor this purpose, such as for example a stamping press having multipleannular cutting dies (adapted to fit snugly over the peripheries of thecylindrical portions 38) of the type which is commercially available andknown in the art.

After being thus severed, the stopper portions form individual stoppers,as shown in Figure 5, wherein the disc-shaped portion 37 constitutes thetop with its lower annular surface forming a downwardly directednyloncoated annular flange 42 (constructed and arranged to makefluid-tight peripheral contact with the rim or lip of a bottle or likecontainer, as shown and described in our aforesaid co-pendingapplication Serial No. 181,194) and wherein the cylindrical portion nowforms the nyloncoated body (constructed and arranged to make fluidtightcontact with the neck of the bottle) and wherein the nylon-coatedsemi-spherical concave surface 40 serves to reduce the thickness ofrubber at the center of the stopper so as to facilitate penetration by ahypodermic afss'siam needle (as;shoimcandfidescribedin ourcmpendingapplication Serial No. F 181, 1-94) 'and whreirrva centraljraised marker 43"is i formed iupon"the'flatvuppr "circular! surface 44 ftramp -37; the rnarker 'flihavingsben formed by the ina'rkengrooves'26described' above. I

1 The upperiportion 45 of:the enerally cylii1drical'peripheralsurface'of the top-31 is an'ioldedsurface (formed by the sides 1 of "the sockets24 as described ab'ove while the lower portion 46 is a cut surface('corresp'ondi'ng to the line of peripheral" cut severing "theindividual stopperportions35 from'the webbing 36).

The stopper 35 ofF-igur'e S'is used"by insert'ing*its ny- Ion-coveredbo'd'y- 'a'o'r 'tion' 38 within the"' neck of'thebottle, ins'nt'lg'ly-fit't'i'ng "slightly coinpress'e'd fluid-tight relatiom shiptherewithuntil its nylon-covered flanged surface 42 makes peripheral'fluid tighficontact "with the'dim Or-lip o'fthe bottle in a mafinershdwnfarid hat-steam described,

in our aforesaid co-pendin'g appli'cation"TSerial No. 1815194. Asheet='mera1*-"'retai other; suitable tneans can be'u curly in placein'the' im'ou'tli ithe bot'tle With'aremovable center portionadaptedtdekpose the'marker 43 preliminary to use. r p

The stopper 35 i c'o structed*aridfarrariged to be readily piercedorpun'ctiti d by ft'he needleof a fhypodermi'c'fsyringe o'rflthe' like,.the pointof'which i's'positioned inside the marker 43 and anua'llyforced through the stopper'at the cente'rr'nbst thinnest portion thereofand also penetratingthe nylon (or otherlsyntheticfresin) film32*geii'erally at the "center offthe semi' spherical surface 40. Thesecur bond .lbetween' the 'fleXible anylo'n. -film and the resilientsoft rubberof thestoppe'rinsur es against detachment of anyx'small'particle of the nylon during penetration of the needle (suchas'wouldf'jintroduce foreign particles into the liquid contents of.the-bottle which might be inadvertently injectedinto apatient,weasel-tans restilts) and, also resultsin substantially re sea'ling fofthe nylon (or other synthetic resin) film when theneedleis withdrawn. Inthis way, theffilm remains substantially to protect the softrubber'ffrom"being' attacked by the liquidcontents offthe"bottle (suchas would result in contamination of 'the'liquid contentsyand permitsthefcontents to be withdrawn, in fractional ainountsffrom time to tlme.

The adhesive composition (for example that described hereinabove) may beappliedto the sti'rfaceof'thenylon (or other synthetic resin 'filrn inliquid .or semi-liquid form vby using any conventional roller-coatinglor knifecoating or brush-coating "apparatus. hesive composition canbesprayed onto the .surfa'ceof the nylon film-,1 using anyconventional'spraygun.

The nylon (orother synth'tic resin) film with-.the a-dhesive ,-s0applied thereto is thenidried in anysuitable oven or heating compartment(at. a temperature sufiiciently low to prevent softening'I of the nylonfilm or 'setting of the adhesive) .to leave.althin.relatively dry'and.nontacky coating of the adhesive upon the surface of the film.

This preliminary drying -ofthe adhesive coatingrnay be executed byradiant heatingelementsor by convectionheating or by a combination ofthe two.

The coatingand drying of the nylon (or othersyntheticresin) film canbecarriedout'as a continuous operation; an elongated strip of thefilm,-in roll "form; being passed over-oneor more coating rollers(which'apply the adhesive to oneside thereof)" and' bythenzpassing thecoated stripthrough anelongatedheatingchamber or tunnel, with thestripsuitably"supported'from .the uncoatedside, in the formofwa moreorless'zstraight'stfip or in festooned formti'. e. looped iover elevatedsupportingarms at spacedintervals) In Figure 8 thereis shown anothersealingcap'orrstopper 47; inter-mediate stages in the"formationj'ofwhich are shown in Figures G and 7. Thus, the strip 48shown in Figure 7 is formed by posi'tioningjan adhesive-coated nyl'onfilm 32 above a sheet 31 'o-f ;i-esili'e'nt' soft'rub beror the like inthe manner describedhc'reinab'ove buteinpl'oying a differentmold'whereinthe recessed 'upper faee 49 of the stationary "lowermoldsection 50"is provided with generally cylindrical socketsor'concavities 51 andwherein'the lower recessed' race 52 0i the movableupper moldsection 53 is provided with matching cylindrical'socktsor'concavities 54. y p p j p when the'iupper moideectien 53 i's'broug-htdo make peripheral contact the drawer -inold sect'in; =the Instead, theadsockets or con'c'avities the generally cylindrical films of nylon (orother somewhat 'le'sser extent) sothat .it 'co'nfori'ns'"to"the con- Theheat and pressure of the molding operation 'also cause'the'therrno-s'etting adhesive to harden"or"set'fso asto pro'vide' a firmand a continuous bond intermediate the f'nylon and rubber surfaces,"'and' thereby"'to"form" a laminated mid-ply structure. v

After cbcflingjthe meld-"is epen'ed and the "stripus; is reiny'ed."The"strip' 48"'inclttdes a plurality of stopperer s55 whicharenior'efor les's cylindrical in confignra'tionand' WHiChEXtlld aboveand below COn-HE'Ctifl'g webbing 5'6. 7 V

One side of the'strt 43 ts "continuously" 'e'ove ed by the imperfo'ratenylon (or other' syh'thticresin)" lm'32 7. The"othe'r si as "shownparticularly 'in"Fi"gur'e (not shown) generall resn1'5les 'th6side"shownin'Figu're 7 eitc'eptjfthat itdoes not have any nylon or othersynthet'icresinyfilmthereon. y p p k lndi'yidu ah stoppers, like that sho wnifiFiglure snare formed from the strip by cutting arot'r'd th' erip eryo'f'the cylindrical stopper por'tions SS 'infan net, as for"'e'iiampleby employing a conv I tiple 'stanjp n machine havingf a pluralityvidu'al annulari tamping 'diesladapted to fit-snugly over the d'ischar ddp r-pmt n fi- The b j film3 2 covers al'l offerteef the flat'circular'walls of the final stopper and, as'can b tieularly in Fig ure 8, alsoextends axially part I I the'cylindrical wall-, as at 57. 'Acentefannula portion 58 of the cylindrical wall of the stopper 55 is ia'cutsu'rface '(eorresponding to the'peripheral line of cufwhers.

by the stopper-portions are' seyered from the'wehbin'g). The otherend'59 of the cylindricalwall of the, stopper 55 is a molded butuneoated surface '(as formed b yfthe '51 in the 'lower"mold=sction50described above) I v i As' shownan'd more fully ldescribedijnou'rfitr'esdid co-pending applicationserial No. 181,194, thestop'per 4555 'o'f Figure 8 isa'daptejd to be used Withjthe coated flat circularside underneath and-making peripheral Contact with jthe 'lip"o rrirn ofthe bottle or othercontainer; suitable fastening means, as for exampleafshe'et-"rtietal retaining-cap (notshown) being employedto clamp thestopper firmly upon the'rim orlip of the bottle, etc! and to maintain itin somewhat-compressed fluid-tight sealing relationship ther with. I v vThe stopper 55 is adapted to be penetrated by the needle of a hypodermicsyringe; theipointof the needle being forced manually downward throughthe softrubber of the stopper andthe nylon (brother synthetic resin)film tolieljow 'the'lev'ehof the liquid contents'of the bottle. Afterwithdrawal of part of thebontent's of the bottle into the hypodermicsyringe, in conventional manner, the needle is withdrawn whereuponthenylon (or othersyntheticresin) film 32 in effect refs'eal's itself soas again to present a substantially continuous nylon surfacewhi'chprotectsthe softrttbberjfrom being acted upon by'the' liquid'contents ofthe bottle. That is,,'the

e combination of the resilience offt he' rubberythe flexibility of thenylon film and the secure bonding action of the intervening heat-setadhesive preventseep'aration of small particles of the nylonfilrn'during passage of the needle therethrough and insures virtual re-sealing of the small hole or puncture made in the nylon film by e edlv ln'figurefll there is shownaniodifib f rm-o1? stopper 474: whichgenerally 'fgseniblesthe s 'r shown in Figure 8 excephthat both fo ffthefiat c cula'r fsides'fof stopper are I "covered by thin syntheticresin).

Asqindica't'edin Figure 9 the s'toppe of Figure I]. is formed bypositioning adhesiveicoatedh'ylon; (brother thermoplastic synthetic1"e's'in)'filin's"32 and 32 above andbelow the softrubbei'she'et 3 1. gp

a reentblin'g the stri "48*desribemab6ve"eXce rtor "the addition of thesecond nylon (or other thermo-setting synthetic resin) film 32-11 on theopposite side of the strip.

The individual stoppers 47-11 are detached from the strip 48-11 byforming a continuous cut around the periphery of each of thestopper-portions, thereby severing the stopper-portions from theintervening double-coated webbing 56-11.

The final stopper 47-11 shown in Figure 11 is identical with the stopper47 except that, as mentioned above, the second nylon film 32-11 coversthe other flat circular side and extends over the adjoining portion ofthe cylindrical wall, as at 59-11. In other words, the coated surface59-11 replaces the uncoated molded surface 59 of the embodiment ofFigure 11 so that the two coated cylindrical surfaces 57 and 59-11 ofthis embodiment are separated by the central cut surface 58.

The method of use of the stopper of Figure 11 is generally the same asthat of Figure 8 except that, as more fully described in our co-pendingapplication Serial No. 181,194, the upper nylon (or other syntheticresin) film 32-1: tends to protect the soft rubber from the action ofany external corrosive chemicals and also to prevent the soft rubberfrom being deteriorated by the action'of the outside atmosphere and,additionally, presents a smooth and impervious surface which can morereadily be cleaned and sterilized prior to penetration of the hypodermicneedle. Just as with the lower film 32, the upper film 32-11 is securelybonded to the soft rubber (to form a generally three-ply structure) sothat there is no separation during passage of the needle and so that thefilm effectively re-seals itself after the needle is withdrawn.

In Figure 13 there is shown a stopper 35-11 which generally resemblesthe stopper 35 of Figure except that its upper surface 44-11, instead ofbeing flat, is somewhat dished or concave to reduce the thickness ofrubber through which the hypodermic needle must pass in penetrating thestopper.

In Figure 12 there is shown an intermediate stage in the method offorming the stopper 35-11.

- Thus, the method of formation of this stopper is exactly the same asthat described hereinabove in connection with Figures 1-5 except that,as shown in Figure 12, the bottom walls 25-11 of the sockets 24-a in therecessed upper face 22-11 of the lower mold-section -11 are somewhatconvex (instead of being flat) so as to form the corresponding dishedsurfaces 44-11 in the stopper-portions 35-11 of the strip 34-11.

The individual stoppers 34-11 in the same manner as describedhereinabove in connection with the strip 34 to give the finalconstruction shown in Figure 13.

As shown and more fully described in our co-pending application SerialNo. 181,194, the point of the hypodermic needle is positioned at thecentermost lowest portion of the dished surface 4-4-1: and is thenmanually forced downward to penetrate the soft rubber and the nylon film32.

As can be seen by comparing Figure 12 to Figure 2, the thickness ofrubber through which the needle must pass in penetrating the stopper isappreciably less in this dished form of stopper so as to makepenetration easier and to lessen the danger of damage to the needle.

In Figure 15 there is shown a stopper 16 which includes a relativelyshort cylindrical body-portion 61 and an enlarged top-portion 62, theupper surface of which is dished as at 63 to reduce the thickness ofrubber through which the hypodermic needle must pass in penetrating theneedle. A continuous and imperforate film 64 of nylon (or otherthermoplastic synthetic resin) is securely bonded to the body-portionand to the downwardlydirected annular flange 65 of the top-portion 62 byan intervening layer of thermosetting adhesive in the manner describedhereinabove.

In Figure 14 there is shown an intermediate stage in the method offorming the stopper 60 of Figure 15.

The method of formation of this stopper is the same as that describedhereinabove in connection with Figures 1-5 except that the bottom walls-11 of the sockets 24-11 in the recessed upper face 22-11 of the lowermold-section 20-11 are somewhat convex as described above in connectionwith Figure 12 while the depressions 28-11 are cylindrical in form.

The individual stoppers 60 are cut from the strip 66 -11 are cut fromthe strip 1 of Figure 16, using any conventional stamping die mechanismto trim away the webbing or flashing 67 around the periphery of the topportion of each stopper.

In Figure 17 there is shown a stopper 35-h which generally resembles thestopper 35 of Figure 5 except that the upper face 22-h of the topportion is dished (as in the stopper of Figure 12 described above) andexcept that the body-portion 38-17 is provided with a generallycylindrical concavity 40-12.

The continuous nylon film 32 covers the cylindrical inner and outersurfaces of the body-portion 38-11 and also the downwardly-directedannular flange 42-11 of the top portion 37-b and is securely bondedthereto by an intervening layer of thermosetting adhesive in the mannerdescribed above.

In Figure 16 there is shown a strip 34-h which represents anintermediate stage in the method of formation of the stopper 35-1) ofFigure 17.

The strip 34-15 is formed by positioning a rubber sheet and a nylon filmintermediate the halves of a heated pressure mold in a manner similar tothat described hereinabove except that, in this case, the knobs or tips29-!) in the annular depressions 28-h formed in the lower face 27-b ofthe upper movable mold-section 21-12 are cylindrical rather thansemi-spherical.

In Figure 19 there is shown a stopper 68 which generally resembles thestopper 47-11 of Figure 11 in that it is formed by a generallycylindrical body-portion 69 of rubber having a continuous film 70securely bonded to the flat circular sides of the rubber and extendingpart way along the cylindrical wall as at 71. A second nylon film 72similarly covers the other flat circular wall of the rubber and extendspart way along the cylindrical wall as at 73; the cylindrical wallhaving an uncoated cut intermediate portion 74 formed thereon.

However, the film 72, instead of being continuously bonded to the rubberas is the film 70, is bonded thereto only along spaced segment-shapedareas 75; there being an unbonded area 76 extending diametrically acrossthe film 72 and down along the portion 73 thereof.

Weakening lines 77 (of perforations) are formed along the sides of theunbonded area 76 so that the nylon film can be grasped and manually tornaway to expose a clean and sterile rubber surface for insertion of thehypodermic needle.

A preliminary stage in the method of formation of the stopper 68 isshown in Figure 18. Thus, in Figure 18 a rubber strip is shownschematically as positioned intermediate the nylon films 70 and 72; thefilm 70 being uppermost and the film 72 lowermost at this stage. Theunder surface of the film 70 is continuously coated with a layer 79 ofdried thermosetting adhesive.

The upper surface of the film 72 is coated with dried thermosettingadhesive only along portions 77 thereof; uncoated areas 76 extendinglongitudinally along the film 72 in alignment with generally cylindricalmoldcavities 80 formed in the recessed upper face 31 of the lowermold-section 82; the cavities 80 being provided with rows of smallspaced proiections 83 which form the weakening lines 77 in the finalstopper 68.

The upper mold-section 84 has cylindrical mold-cavities 85 formed in itsrecessed lower face 86 in line with the mold-cavities 80 and generallyidentical therewith except that the projections are omitted.

When the mold sections 32 and 84 are brought together, the rubber andthe nylon films are forced into the form of the mold-cavities under theaction of the heat and pressure. At the same time, bonding occursbetween the nylon and the rubber in those areas of the nylon films whichwere coated with the thermosetting adhesive. However, along the uncoatedarea 76 of the nylon film 72, no bonding action takes place; the nylonsimply fitting snugly over the rubber in this area so as .to keep therubber surface clean and sterile and, at the same time, to permit theportion of the film intervening the weakening lines 77 to be readilytorn away preliminary to insertion of the hypodermic needle.

In Figure 22 there is shown a modified form of stopper 68-11 whichgenerally resembles the stopper 68 except that the nylon film 72-11 isco-extensive with the flat circular wall of the body-portion and doesnot extend along the cylindrical wall thereof.

In Figures 20 and 21 there are shown intermediate stages in the methodof formation of the stopper 68-11.

According to this embodiment, the continuous nylon mentwshaped areas17541,

. 72 is replaced by. a plurality of. separateindividual the ;-moldcavities 89%; in the .lower; mold-,seetion ska (.the mold cavities 8t}abeing .identicalywith; the=;mold cavities- 80 except that theprojections 83 are omitted therefrompafter which the upper moldt seetion84 is brought down to for-mtherubber and nylon 'into; the desiredconfiguration and ofthe nylon film- "Mite-one side of the rubberstrip-Q87 and partialbonding of the nylon. discs 72-a;to-:t-he oppositeside of the rubber-stri ,rat; the stopper-portions-fiiim h ft Cf:

\ After the, mold is open, the strip fsl-tshown in-i Figure 21, isremoved therefrom, after which the',stopper .-portions tifi-a are cutfrom, thenstrip by trimmingt 011?; the webbing-or flashing 33 (which; inthis-embodiment-,.; is nylon-coated only alongone surface-thereof)inefmanher-similar to that described hereinabove.

' The unbonded center areafld-a of. the nylon film ll a can- .begraspedan d manually tornawayalongthe weakening lines 77 a so as to expose aeleanandsterile,rubher surface for penetration by thehypodermic needle.-

ln Figures 25 and 26 -there is shown a .;stoppers8;9,ineluding agenerally cylindrical body-portion 90 having a cylindrically-concaveinner surface 9 l, and including an enlarged'top '92 providing anannular downwardly-dirested flangel93 constructed andarranged-to seatagainst the upper annular surface 94 of the lip 95 of a-bot-tle(or'other similar container) 96, when the body po'rtion 90 is insertedwithin the mouth 97'ofis'aid bottle A relatively thin tubular resilientgrippingsleeve'fls is formed integrally with'thetop 92'and-extends"?generally axially upwardly from the periphery thereofasiindie'ated in Figure 25; the sleeve 98"beingfoldable' downward uponitself to bring' itsan'nular freeedge 99 below the gop 92m a manner tobe described more fully hereinelow.

A thin'eontinuous film ltltl'ofnylon' '(or other'syrithetic resin) issecurely and continuously bonded to the soft rubber of the stopper; thefilm 190 covering the inner and outer surfaces of the body-portion 99and also the flange 93 of the top 92; the film preventing chemical (orother) interaction between the soft rubber of the stopper and thecontents of the bottle 96 such as might contaminate such contents orrender them ineffective and/or harmful for medicinal purposes.

The stopper 89 is used by first inserting the body-portion 90 into themouth 97 of the bottle 96 with the gripping-sleeve 98 extending upwardlytherefrom as indicated in dash-dot lines in Figure 6. In this position,the cylindrical outer wall of the body portion 90 makes continuousfluid-tight sealing contact with the inner wall of the mouth 97 whilethe flange 93 is seated against the upper surface 94 of the lip 95. v

The upper free edge 99 of the gripping-sleeve 98 is then turneddownwardly and outwardly so as to invert the sleeve upon itself and tocause the gripping-sleeve 98 to extend downward from the top 92, inenveloping relationship to the enlarged lip 95 of the bottle 96, withthe annular free edge 99 firmly gripping the neck 101 of the bottle 96somewhat below the lip 95, as indicated in solid lines in Figure 26.Since the diameter of the neck 101 is somewhat greater than the normaldiameter of the gripping-sleeve 98, the latter is stretched somewhatwhen in its downwardly-extending gripping position as shown in solidlines in Figure 26. This results in a secure gripping action andmaintains the stopper firmly in place within the mouth of the bottle;the frictional retaining force exerted by the sleeve upon the neckpreventing accidental dislodgment of the stopper.

However, the free edge 99 can be readily rolled up ward, manually, toreturn the sleeve 98 to its original upwardly-extending position topermit removal of the stopper (as, for example, in order to refill theempty bottle). The upper relatively flat circular surface 102 of the top92 (i. e. the surface surrounded by the upwardlyextendinggripping-sleeve 98) may, optionally, be provided with a relatively thindisc 103 of nylon (or other to cause continuous bonding .dried-ther 10synthetic-resin) ,the" .disc ltldgbeing adhesivelyibondedrtothe-surfacel02 only along .segmentrshapeld areasul04 with adiametrically-extending?.unbonded area. 105' disposed- -therebetween. I

When thegrippingsleeve 98 is :lIl itsturned-downtgripping position, thenylon disc-.103 can-she 3 grasped atgthe free edge of itssunbondedportion 105': and manually. torn away; to expose acleantsterile'rubberasurfacetfor penetration by the hypodermicineedleIf-desired; parallel weakening lines 106' (of-perforationsiymaybe formedon the unbonded portion of the disc, 103: toa'facilitate the tea-ringaway thereof.

A preliri'rinary. stage; in the methodof formingthe stopper-891is showninFigure 24.

Thus, in Figure. 24, there are shown upper. and lower mold sections-ltliand, 108 provided with aligned annular mold-sockets .or concavities11019 and respectively. The over-all diameter of the-mold-sockets 109?islessthan the over-all diameter of the mold-sockets 110 but) the-.radialdimension er. thickness of the annular. concavities 109. isgreater,than-that of the annular concavities 110-.

Thein dividual nylon discsJttlS (which havepreviously been cut to sizeand coated withdried thermo-setting adhesive along the spacedgment-shaped areas 104) are positioned upon the upper circular wallsofi-the-knobs or tipslil1'.oft,the;lo wer mold-sockets itlltl with theadhesivccoated side of the disc;upperm ost. The .rubbersheet andtheuppencontinuous nylon film Zltltli(the under surface ofwhich;.has.;previously been continuously coated with .tting;adhesive-ina manner s'imilanto that described nabove) 1 are. then positionedintermediate the mold-sections 11 07 and ;,ll 0j8, [which are thenbrought together; the heat-and pressure ofithemold causing'the upp rnylon film I 100 and therubber sheet. to soften and .flow' into the gvconfiguration ofthe mold =concavities-in the manner indicated inQFigure.24.

At the sameatime the. heat and pressure of the .mold cause, the-thermo-setting adhesivetoharden or set thereby creating .a continuousbond between the. upper nylonfilrn l iltlfand the juxtaposedsurfaces ofthe molded: strip,112

and also creating "a bond between th'e adhesive coated areas 104, of.theindividual nylon discs 103 andthe juxtaposed; rubber fsur'fa'cesofithestrip 112.}

Themoldjsfthenjcooled"and'opened and the strip .112

I U vedjtherefrom; whereupon the individual stoppers .89 are'cut"fromthe strip '112by" trimming off the" webbing or flashing 113 around theperiphery of the top 92.

Any conventional stamping device (as, for example, one employingmultiple annular cutting dies of a diameter enabling them to fit snuglyaround the sleeves 98) can be employed for this cutting operation.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiments be considered in allrespects as illustrative and not restrictive, reference being had to theappended claims rather than to the foregoing description to indicate thescope of the invention.

Having thus described our invention, we claim as new and desire toprotect by Letters Patent:

1. A method of forming a ncedle-penetrable stopper for a container whichincludes the steps of fully coating one face of a thin flexible butrelatively non-resilient film of thermoplastic synthetic resin with athermosetting adhesive, partially coating one face of a second thinflexible but relatively non-resilient film of thermoplastic syntheticresin with thermosetting adhesive, positioning said films on either faceof a somewhat thicker sheet of thermoplastic resilient soft elastomerwith the coated faces facing inwardly, and subjecting said films andsaid sheet to molding temperature and pressure thereby to form them intothe desired stopper configuration and at the same time to cause theadhesive to set so as to create a secure bond between the resin filmsand the juxtaposed molded elastomer surfaces, with the uncoated portionof the second film providing an unbonded removable portion of such filmin the final stopper.

2. A method according to claim 1 wherein the first mentioned resin filmis generally coextensive with the elastomer sheet and wherein a striphaving a plurality of stopper-portions connected by relatively thinwebbing is first formed, using a multi-cavity mold, the first-mentionedresin film forming a continuously-bonded imperforate coating on one faceof the strip, and wherein a plurality of relatively small individualpieces of synthetic resin film are provided on the other face of theelastomer sheet, said individual pieces being adhesivelycoated onlyalong spaced areas thereof with an intervening uncoated area wherebysaid individual pieces are bonded to the strip only at thestopper-portions thereof with the intervening uncoated areas unbonded,and

wherein the individual stoppers are subsequently formed by trimming awaythe webbing of the strip around the periphery of each stopper-portion.

3. A method according to claim 1 wherein the first mentioned resin filmis generally coextensive with the elastomer sheet and wherein a striphaving a plurality of stopper-portions connected by relatively thinwebbing is first formed, using a multi-cavity mold, the first-mentionedresin film forming a continuously-bonded imperforate coating on one faceof the strip, and wherein the second synthetic resin film is alsogenerally coextensive with the elastomer sheet, said second film havingrelatively small uncoated areas extending in alignment with thestopper-portions, and wherein the individual stoppers are subsequentlyformed by trimming away the webbing of the strip around the periphery ofeach stopper-portion, whereby the first-mentioned resin film forms acontinuously-bonded covering on one face of the stopper while thesecond-mentioned resin film forms a partially-bonded covering on theother face of the stopper with the unbonded portion detachable from thestopper.

4. A method of forming a needle-penetrable stopper for a container whichincludes the steps of fully coating one face of a thin film of nylonwith a thermosetting adhesive, partially coating one face of a secondthin film of nylon with thermosetting adhesive, positioning said filmson either face of a somewhat thicker sheet of rubber with the coatedfaces facing inwardly, and subjecting said films and said sheet tomolding pressure thereby to form them into the desired stopperconfiguration and at the same time to cause the adhesive to set so as tocreate a secure bond between the nylon films and the juxtaposed moldedrubber faces, with the uncoated portion of the second film providing anunbonded removable portion of such film in the final stopper.

5. A method according to claim 4 wherein the firstmentioned nylon filmis generally co-extensive with the rubber sheet and wherein a striphaving a plurality of stopper-portions connected by relatively thinwebbing is first formed, using a multi-cavity mold, the first-mencoatingon one face of the strip, and wherein a plurality of relatively smalldiscrete individual pieces are provided on the other face of the rubbersheet, said individual pieces being adhesively-coated only along spacedareas thereof with an intervening uncoated area whereby said individualpieces are bonded to the strip only at the stopper-portions thereof withthe intervening uncoated areas unbonded, and wherein the individualstoppers are subsequently formed by trimming away the webbing of thestrip around the periphery of each stopper-portion.

6. A method according to claim 4 wherein the firstmentioned nylon filmis generally co-extensive with the rubber sheet and wherein a striphaving a plurality of stopper-portions connected by relatively thinwebbing is first formed, using a multi-cavity mold, the first-mentionednylon film forming a continuously bonded imperforate coating on one faceof the strip, and wherein the second nylon film is also generallyco-extensive with the rubber sheet, said second nylon film havingrelatively small uncoated areas extending in alignment with thestopper-portions, and wherein the individual stoppers are subsequentlyformed by trimming away the webbing of the strip around the periphery ofeach stopper-portion, whereby the first-mentioned nylon film forms acontinuously bonded covering on one face of the stopper while thesecond-mentioned nylon film forms a partially bonded covering on theother face of the stopper with the unbonded portion detachable from thestopper.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,482,045 Stearns Jan. 29, 1924 2,227,212 Beck Dec. 31, 19402,449,180 Schroeder Sept. 14, 1948 2,497,454 Illingworth et al Feb. 14,1950 2,499,724 Compton Mar. 7, 1950 FOREIGN PATENTS Number Country Date423,856 Great Britain Feb. 5, 1935

1. A METHOD OF FORMING A NEEDLE-PENETRABLE STOPPER FOR A CONTAINER WHICHINCLUDES THE STEPS OF FULLY COATING OF FACE OF A THIN FLEXIABLE BUTRELATIVELY NON-RESILIENT FILM OF THERMOPLASTIC SYNTHETIC RESIN WITH ATHERMOSETTING ADHESIVE, PARTIALLY COATING ONE FACE OF A SECOND THINFLEXIBLE BUT RELATIVELY NON-RESILIENT FILM OF THERMOPLASTIC SYNTHETICRESIN WITH THERMOSETTING ADHESIVE, POSITIONING SAID FILMS ON EITHER FACEOF A SOMEWHAT THICKER SHEET OF THEREMOPLASTIC RESILIENT SOFT ELASTOMERWITH THE COATED FACES FACING INWARDLY, AND SUBJECTING SAID FILMS ANDSAID SHEET TO MOLDING TEMPERATURE AND PRESSURE THEREBY TO FORM THEN INTOTHE DESIRED STOPPER CONFIGURATION AND AT THE SAME TIME TO CAUSE THEADHESIVE TO SET SO AS TO CREATE A